This invention relates to a method for attaching cladding and other body panels onto a vehicle.
Plastic outer body panels have become more frequently used over metal body panels. Plastic is advantageous over metal in order to reduce vehicle weight and improve corrosion resistance Additionally, plastic panels are less susceptible to damage from minor impacts.
Attachment of plastic panels to the metal substrate of the vehicle poses several problems. First, plastic and metal are incompatible for welding. Second, plastic panels must be mounted without distortion as such distortion is visible. Third, plastic and metal have different rates of thermal expansion. Fourth, certain plastic panels have relatively high rates of hydroscopic growth in conditions of high humidity.
In U.S. Pat. No. 4,529,244, a plastic body panel is provided with fasteners spaced about the panel. These fasteners allow for relative sliding movement between the panel and the metal substrate. To attach the upper edge of the panel, a plastic reinforcement is attached to the back surface of the panel. The fasteners are retained by the reinforcement. To attach the lower edge of the panel, the fasteners extend through the panel into the substrate, requiring a special tool to close each fastener.
In U.S. Pat. No. 4,973,102, a plastic body panel is provided with fasteners. A special bracket is mounted on the vehicle and the plastic panel is fastened to the bracket. The plastic panel has longitudinal slots which allow relative movement between the plastic panel and the vehicle substrate.
The plastic panel attachment methods of the prior art have not been completely satisfactory. The plastic panels have been know to exhibit a xe2x80x9cropingxe2x80x9d effect, where the panels sag between the attachment points. In other plastic panels, complicated moldings are required for the fasteners which result in an increase incidence of sink marks on the front face of the panel.
The disadvantages of the prior art may be overcome by providing a simple method of attaching a plastic panel to a vehicle substrate.
It is desirable to provide a method for attachment of a plastic panel to a vehicle substrate, which method allows to relative expansion of the plastic panel relative to the vehicle substrate.
According to one aspect of the invention, there is provided a mounting method for mounting a plastic panel to a vehicle substrate. There is provided a support flange on an inner surface of the panel. A reference nodule is positioned on the inner surface of the panel. An elongate bracket has an upper edge thereof engaging the support flange. The bracket has a reference notch engaging the reference nodule positioning the bracket relative to the panel. A plurality of retainers is mounted on the bracket. A double-sided adhesive tape has a first adhesive on a first side thereof compatible for adhesion to the bracket and a second adhesive on a second side thereof compatible for adhesion to the panel. The first side of the adhesive tape is applied to the bracket and the second side is applied to the panel. The tape allows expansion and contraction movement of the panel while securely retaining the panel to the vehicle substrate.
According to another aspect of the invention, there is provided a retainer. The retainer has an arrow shaped body having an axial extent and a pair of opposing tangs biased to permit only insertion of the retainer in a complementary aperture. A flange extends from the body and is positioned to limit insertion of the retainer in the complementary aperture. A stud is axially spaced from the flange. The stud has a non-circular shape. A tab extends from the flange towards the stud and is rotationally spaced therefrom. A non-circular aperture is provided on a mounting surface. The aperture is sized to receive the stud, wherein the retainer is mounted by inserting the stud through the non-circular aperture and the retainer is rotated until the tab snappingly engages the noncircular aperture locking the retainer to the mounting surface.